Decision on Zeobrite or Sand replacement

[duraleigh]

Hi, Tom,

If it's possible, try to eliminate all the other variables when you change the sand and let us know what you find out. After saying that, I have no idea how you can retain the dead algae in your pool while you change sand but maybe we'll all get an indication if your effort was effective. Good luck with it and let us know

Dave S.

[CarlD]

Ammonia is released into a chlorine filled pool if you use an SWG? Excuse me, but doesn't mixing ammonia and chlorine result in a deadly gas being produced, which is why you are warned to NEVER mix the two for home cleaning?

If you put DE in your sand filter, you'll probably have to add more every time you backwash. Since you only add a half/cup to a cup, a 10-15 lb box should EASILY last the season. I use this method as well and like it.

[waterbear]

Ammonia is released into a chlorine filled pool if you use an SWG? Excuse me, but doesn't mixing ammonia and chlorine result in a deadly gas being produced, which is why you are warned to NEVER mix the two for home cleaning?

If you put DE in your sand filter, you'll probably have to add more every time you backwash. Since you only add a half/cup to a cup, a 10-15 lb box should EASILY last the season. I use this method as well and like it.

The ammonia will be in the form of ammonium ions. These are what combine with chlorine in the pool to form chloramines (VERY simplified chemical explanation!)
From my understanding some "old time pool service guys" would put anhydrous ammonia and liquid chorine into a pool to purposely form chloramines and then reach 'breakpoint' by putting more chlorine in 24 hours later. The chloramines are eaten by algae and decolorizes it. Some commercial algae products also put ammonia compounds into the water for the same reason (Black Algaetrine comes to mind)
Also many water treatment facilities put ammonia or ammonia compounds into the water with the chlorine to form simple chloramines to prevent the formation of more toxic ones. (this has been a major headache to every aquarium hobbiest for years now and forced us to learn all about "breakpoint chlorination" even if we never owned a pool! since ammonia is MUCH more toxic to fish and other livestock than chlorine is and choramines are MUCH harder to get rid of then chlorine.)

But you are right, mixing liquid ammonia and liquid chlorine CAN release deadly fumes and should be avoided! The difference is most likely the dilution factor involved.

[TMan]

Thx waterbear. I really didn't want to start to explain that saltwater is the recomended cleaning agent for zeolite, and when it 'cleans' the zeolite it is widely known that it releases stored ammonia from the zeolite. Therefore, if you're running a swg constantly, the zeolite is constantly being 'cleaned' then ammonia is constantly being released. Obviously it will be in such minute amounts, and dilution as you point out below, that it will not be an issue what-so-ever. And to take it to a farther logical point, will zeolite ever be able to 'absorb' any amount of ammonia if saltwater is passing over it?
Which makes the whole question of ammonia release kinda moot.
My issue was that I didn't want to invest in z-lite if this cleaning ability is one of it's strong points and I was stifling it by using the media in an swg pool.
I'm replacing my sand anyway so it doesn't matter.

Guess we did end up 'splaining it, Lucy!
Tom

[TMan]

UPDATE: Replaced 250lbs of sand saturday, April 22. Today, water is 85-90% clear and clearing nicely. Added 2x40lbs bags of salt, SWG is running at 3000ppm salt level and generating nicely. The surface of the vinyl is very rough, must be algae that scaled on there. It won't come off with a stiff poly brush, but will come off with some gentle wipes with a 'green' pad. Anyone ever run into this? Guess everyone will get a green pad to wear on their feet for a week's worth of swimming!
Thanks for the tips, tricks and 'listening'.
Later
Tom

[duraleigh]

Hi, Tom,

Thanks for the follow-up. That's a very interesting comment about your vinyl liner.

It won't come off with a stiff poly brush, but will come off with some gentle wipes with a 'green' pad.

I'm not positive, but I don't think that's algae. When I review your first post, I see this:

but the problem is just like some other posters, the fine algae is going through the sand filter.

That leaves a milky-white pool which I've been vaccuming every day and haven't seen the bottom of for 2 weeks

Combining those two observations makes me think that something precipitated out of your water and has scaled on the vinyl.....perhaps calcium.

To my knowledge, algae dead or alive doesn't create a scaling condition. Nor does dead algae turn a pool milky white (to my knowledge)...more like cloudy grayish blue.

Well, if your water looks nice, that may be enough. I believe I would look at my test numbers very carefully....I think there was something else going on. Have you done a complete test this Spring?

[TMan]

Dave,
I think there may be some calc precipitated out.
I tested about 3 days after I went back to regular chorination (during/after sand change my FC was +15) and we went clear.
According to my handy-dandy ps233 -
FC=3.5 CC=0 TC=4 pH=7.8 Alk=190 Cal=240 Cya=0 (week ago)
I retested 2 days ago FC=4 CC=0 TC=4.5 ph=8 Alk=210 Cal=270 Cya=20

The calc is coming off with a green pad but the 'gentle wipes' in some spots translate to "you gotta scrub".
Since I run a SWG my ph is always high, and were in central TX, nothing but the best mineral water in the west. Filtered by the limestone rocks and pumped out of the aquifer, clogging shower heads and coffee pots in a city near you!

Anyway, I'm not looking for quick fix, I know this will take work, But if you know of anything that could help soften up some of that calc to make it easier when scrubbing every inch by hand please pass it on.
Oh, and since were very far (weatherman says ~20") behind in rainfall for 12 months running, every week I just add more of that mineral water back to the pool for top-off, durn.
Thx all,
Tom